Speed change device



E. A. RYDER Dec. 15, 1931.

SPEED CHANGE .DEVICE Filed Nov. 21

R O T N E V m ATTORN EY Patented Dec. 15, 1931 EAR-LE RYDER, 'OF WEST EARIFORD,

CONNECTICUT, ASSIGNOR TO T KE PRATT dz.

WHITNEY AIRCRAFT 00., OF HARTFORD, CONNECTIG'UT, A. CORPORA.TION F DELA- 'WABE srnnn CHANGE nnvrcn I Application filed November 21, 1928. Serial No. $520,977.

This invention relates to speed change devices, and in particular to a gear type speed reduction unit disposed between an aircraft en e and its propeller.

primary object of the invention is to provide a, gear reduction unit between the crank-shaft and propeller hub of an aircraft engine which will be simple in construction, light in weight, have few parts, and which w1ll be efficient in operation.

An important feature of the invention is to provide'an extended ortion on the crankshaft surrounded by a s eeve, the crank-shaft and sleeve having mtermeshing gears thereon, and to provide supporting means for these two members which is adapted to support them accurately and rigidly in proper relative position.

Another object of'the invention is to provide a bearin for the extended portion of the crankshafg and the sleeve to which the propeller hub is attached adapted for supporting these members rotatably relatively to each other upon parallel axes.

.A further object of the invention is to provide a (gear on an intermediate portion of the exten ed crank-shaft meshing with another gear preferably of the internal type on the inner end of the driven sleeve surround- 3o the crank-shaft so that the sleeve may be driven at a different speed from the crankshaft substantially silently and with a minimum of additional weight and space being...

l rotatably support a crank-shaft and sleeve: forming parts of a speed change device applied to an aircraft engine, preferably by spaced antifi-iction bearin s the inner rings thereof respectively engagmg the hub ofthe driving gear and the sleeve adjacent the driven gear, the outer'rings of these bearings being supported within members of the e frame within which the crank-shaft an sleeve are mounted.-

With the" above and other objects in view -my invention includes the features of construction and operation set forth in the followingspecification and illustrated in the accompanying drawings.

still further object of the invention is to,

In the drawingsa Fig. 1 is a longitudinal sectional view through the propeller end of an aircraft en gine showing my improved form of speed reducing device applied thereto;

Fig. 2 is a transverse sectional view taken upon the plane of line 22 of Fig. 1; and

ig. 3 is a similar sectional view taken upon the plane of line 3-3 of Fig. 1.

In the above mentioned drawings I have shown but one embodiment of my invention applied to an aircraft engine, but it will be understood that the invention can be otherwise embodied and that the drawings are not 7 the engine is driven at its highest efficient speed to develop maximum power, and the p'ropelleris driven at a reduced speed relative to the engine in order to use the propeller at its maximum efficiency. One eng'ne may be used in a lar e variety of aircra requiring for their efficient operation propellers of widely different characteristics. This calls for a large number of different speed ratios between the engine crank-shaft and its propeller depending upon the particular pro- :peller with which the engine is used. The

present invention relates more particularly therefore to a reducing unit adapted to be interposed between the crank-shaft of an air craft engine and the pro eller hub thereof which will permit a wi e selection in the members so that the unit may be designed for any one of a large number of ratios.

Referring more in particular to the figures of the drawings, the forward or propeller end of a crank-shaft 10 is shown rotatably mounted-within a portion of the en 'ne housing forming the crank case 11. Thls driving shaft 10 for. the ropeller (not shown) is extended forward y so that it extends completely through the front housing 12 of the engine frame. Surrounding the forward portions 13 of the crank or driving shaft 10 of e the en 'ne is a sleeve 14 mounted rotatably over t e driving shaft upon a supporting member 15. This supporting member-l5is interposed between the outer surface of the 5 forward portions 13 of the driving shaft and the inner cylindrical surface of the driven shaft or sleeve 14. Thissupport for the sleeve 14 surrounding the driving shaft is preferably made integral with a 10 flanged member 16 bolted at its periphery to one ofthe housing members 17 of the frame. As shown clearly in Fig. 1 the front end of the crank case 11, the member 17 forming part of the engine-frame and thefront clo- 15 sure member 12 are all securely bolted together. The flange -member 16 forming a portion of the supporting member 15 is bolted, preferably as shown, between the members 17 and 12. In this manner the sup porting member 15 is held rigidly in position and aids in supporting the extended portions 13 of crank shaft 10. The sleeve or .driven shaft 14 is supported rotatablyupon outer cylindrical bearing surfaces formed on the supporting member 15.

Mounted upon the outer cylindrical portion of the driven sleeve 14 adjacent its rear end is an antifriction bearing 18 the inner ring of which engages the sleeve 14 'and the 39 outer ring engages an internal surface in the surroundmg housing member 12. The sleeve 14 therefore is rotatably supported upon and is guided by the bearingmember 15 between itself and the driving shaft 13. In addition 35 it is further supported adjacent itsrear end with relation to the housing member- 12 by the antifriction bearing 18.

Mounted on anintermediate part of the driving shaft 13 is a driving ear 19, the hub 49 portion of which is splined or engagement with corresponding splines in the shaft 13 and is extended on one side to form a hearing or seat for the inner ring of an antifriction bearing 20. The outer ring of this hearing 20 Y engages the flanged portion 16 of the supporting member 15. The driving gear 19 is retained in axial position upon the shaft 13 by means of a collar 21 threaded upon the shaft 13 in advance of the gear 19 and pinned 59 in adjusted position. g

The rear end of the sleeve 14 is enlarged in diameter as indicated clearly in Fig. 1 and is provided at its inner end with an internal gear 22. This internal gear 22 meshes directly with the teeth of the gear 19 on the driving shaft 13 which is of the spur type. As is shown clearly in Fig. 2, the axes of the driving shaft 13 and the driven sleeve 14 are parallel and are disposed in a common vertical plane, the axis of the driven sleeve 14 being a material distance from and preferably below that of the driving shaft 13. The gears 19 and 22 therefore will mesh, in the embodiment of the invention illustrated in 35 Fig. 2, above the axes of its shaft 13 and sleeve 14 and a crescent shaped opening will sleeves 14 and supporting members 15 the construction may be adapted for any predetermined speed ratio between relatively wide limits. Furthermore, by removal of the sleeve member 15 and substituting a new frame member 12 and bearing 18 to take the place of the frame member and bearing shown in the drawings a propeller may be mounted directly upon the forward end of the driving shaft 1 t The driving shaft 13, as will be seen by reference to Fig. 1, is supported adjacent and directly in front of the crank'23 by the usual bearing 24 preferably of the antlfriction type contacting With a surface of the crank case 11, and will be further supported by an antifriction bearing 20, the inner ring of which engages the hub of the gear 19 secured upon this driving shaft 13. Further-- more, the driving shaft 13 Will be supported by means of the antifric'tion bearing 18 mounted upon the rear end of the driven sleeve 14 acting through the bearing 15 between the shaft 13 and sleeve 14. The outer or free end of the driving shaft 13 will be di-' rectly supported by the intermediate supporting member 15 which forms a plain bearing both for the driving shaft 13 and the driven sleeve 14. The driving shaft 13 and sleeve 14 therefore materially support. each other through the supporting member 15 extending between them. The bearing surfaces on this supporting member are spaced apart, the intermediate portions being suitably recessed. In order to reduce the weight of the supporting member 15, holes 25 may be bored and recesses formed therein in various' portions of this member 15 and its flanged portion 16.

I claim:

1. A speed change device comprising incombination, an e frame, a drivin shaft therein extending forwardly throug said frame, a driving gear on an intermediate rtion of said driving shaft, a driven shaft in the form of a sleeve eccentrically surrounding said driving shaft, a hearing between said driving shaft and frame, a bearing between said driven shaft and frame, and a supporting member having bearing ortions for said driving and driven shafts posed between said shafts.

3.,A speed change device comprising in combination, .an en 'ne frame, a driving shaft therein extending completely through said frame, a drivin gear on an intermediate portion of said driving shaft,'a driven shaft in the form of a sleeve eccentrically surrounding and with its axis parallel to said driving shaft, a bearin between said driving shaft and frame, a aring-between said driven shaft and frame, a bearing between a portion of said driving gear and said frame, and'a bearing disposed between said driving shaft and said driven shafts.

- 4. A s ed change device comprisin in combination, an en ne frame, a driving s aft therein extendingt rough said frame, a. drivin ar on an intermediate portion of said driving shaft, a driven shaft in the form of a sleeve eccentrically surrounding andiwith its axis parallel to said drivin shaft a bearing between said driving sha and frame, a

bearing between said driven shaft and frame, fa sigpsporting member disposed between said sha and spaced bearing portions on said driving and driven shafts engaging said supporting member.

'5. A speed change device comprisin in "combination, an engine frame, a driving s aft therein'extending through said frame, a drivs ing gear on an intermediate portion of said driving shaft, a driven shaft in the form of v a' sleeve eccentrically surrounding and with its axis parallel to said driving shaft'bearin for said driving and driven shafts rotatjab y supporting said shafts relative to said frame, and a supportin member disposed between said drivingan driven shafts, said supporting member extendin 7 between the space between said gears and at (itsArear end to said frame.

combination, an engine frame, a driving shaft therein extending throu h said-frame, a

driv' g'earon an interm late portion of said driving shaft, a driven shaft in the form of a sleeve surroundin said shaft, a bearing for said drivin and riven shafts rotatably aftzand enclosed by said riven shaft having bearing surfaces e by said driving and driven shafts, an means to hold said supporting mber in '(1 position relativetosaid frame.

driving sha tween said frame and one end of said sleeve,

driving sha .gear thereon in mesh with said driving ing attached d change deviee comprising in 7. A speed reducing device comprisin in combination, an engine frame, a driving s aft therein, a driving ar on an intermediate portion thereof, a riven. shaft in the form of a sleeve surrounding a portion of said driving shaft, a gear thereon in mesh with said drivin gear, a bearing between said and said frame, a hearing beand supportin means for the extended portions of said rivin and driven shafts disposed betweemsaid s afts.

8. A speed reducing device comprisin in combination, an engine frame, a driving s, aft therein, a driving ear on an intermediate portionithereof, a riven shaftin the form ofa sleeve surrounding a portion of said driving shaft, a gear thereon in mesh with said drivin gear, a bearing between said and said frame, a bearing between said frame and one end of said sleeve, and supporting means for the extended ortion of said driving shaft and for said riven shaft disposed between said shafts and attached at its rear end'to said frame.

9. A speed reducing device comprisin in combination, an engine frame, a driving s aft between said frame and one of said sleeves,

and supportin means for the extended portions of said riving and driven shafts disposed between ,said shafts, said supporting means extending through the space between.

said ears and havin a flange at its rear end attac ed at its perip e to said frame.

10. A speed change evice comprisin in combination a plurality of members rigidly secured together to form a support, a driving shaft rotatably mounted within said support a gear provided with a hub extension on said shaft, a bearin between the said extension and one of said members, a driven shaft mounted within said support and having a a bearing supporting one end of said driven and an extension of said driving shaft for supporting said driven shaft.

- EARLE A. RYDER.-

115 shaft, and means between said driven shaft 

